92 research outputs found
Environmental benefits of leaving offshore infrastructure in the ocean
© The Ecological Society of America The removal of thousands of structures associated with oil and gas development from the world's oceans is well underway, yet the environmental impacts of this decommissioning practice remain unknown. Similar impacts will be associated with the eventual removal of offshore wind turbines. We conducted a global survey of environmental experts to guide best decommissioning practices in the North Sea, a region with a substantial removal burden. In contrast to current regulations, 94.7% of experts (36 out of 38) agreed that a more flexible case-by-case approach to decommissioning could benefit the North Sea environment. Partial removal options were considered to deliver better environmental outcomes than complete removal for platforms, but both approaches were equally supported for wind turbines. Key considerations identified for decommissioning were biodiversity enhancement, provision of reef habitat, and protection from bottom trawling, all of which are negatively affected by complete removal. We provide recommendations to guide the revision of offshore decommissioning policy, including a temporary suspension of obligatory removal
Assessment of safety and feasibility of a new technical variant of gastropexy for percutaneous endoscopic gastrostomy: an experience with 435 cases
Location of the CD8 T Cell Epitope within the Antigenic Precursor Determines Immunogenicity and Protection against the Toxoplasma gondii Parasite
CD8 T cells protect the host from disease caused by intracellular pathogens, such as the Toxoplasma gondii (T. gondii) protozoan parasite. Despite the complexity of the T. gondii proteome, CD8 T cell responses are restricted to only a small number of peptide epitopes derived from a limited set of antigenic precursors. This phenomenon is known as immunodominance and is key to effective vaccine design. However, the mechanisms that determine the immunogenicity and immunodominance hierarchy of parasite antigens are not well understood.Here, using genetically modified parasites, we show that parasite burden is controlled by the immunodominant GRA6-specific CD8 T cell response but not by responses to the subdominant GRA4- and ROP7-derived epitopes. Remarkably, optimal processing and immunodominance were determined by the location of the peptide epitope at the C-terminus of the GRA6 antigenic precursor. In contrast, immunodominance could not be explained by the peptide affinity for the MHC I molecule or the frequency of T cell precursors in the naive animals. Our results reveal the molecular requirements for optimal presentation of an intracellular parasite antigen and for eliciting protective CD8 T cells. © 2013 Feliu et al
Protective Efficacy of Serially Up-Ranked Subdominant CD8+ T Cell Epitopes against Virus Challenges
Immunodominance in T cell responses to complex antigens like viruses is still incompletely understood. Some data indicate that the dominant responses to viruses are not necessarily the most protective, while other data imply that dominant responses are the most important. The issue is of considerable importance to the rational design of vaccines, particularly against variable escaping viruses like human immunodeficiency virus type 1 and hepatitis C virus. Here, we showed that sequential inactivation of dominant epitopes up-ranks the remaining subdominant determinants. Importantly, we demonstrated that subdominant epitopes can induce robust responses and protect against whole viruses if they are allowed at least once in the vaccination regimen to locally or temporally dominate T cell induction. Therefore, refocusing T cell immune responses away from highly variable determinants recognized during natural virus infection towards subdominant, but conserved regions is possible and merits evaluation in humans
A CRISPR platform for targeted in vivo screens identifies Toxoplasma gondii virulence factors in mice
Towards improving the safety and diagnostic yield of stereotactic biopsy in a single centre
Background: Previously, we reported on our single centre results regarding the diagnostic yield of stereotactic needle biopsies of brain lesions. The yield then (1996-2006) was 89.4%. In the present study, we review and evaluate our experience with intraoperative frozen-section histopathologic diagnosis on-demand in order to improve the diagnostic yield. Methods:
Multizone Paper Platform for 3D Cell Cultures
In vitro 3D culture is an important model for tissues in
vivo. Cells in different locations of 3D tissues are
physiologically different, because they are exposed to different concentrations
of oxygen, nutrients, and signaling molecules, and to other environmental
factors (temperature, mechanical stress, etc). The majority of high-throughput
assays based on 3D cultures, however, can only detect the
average behavior of cells in the whole 3D construct.
Isolation of cells from specific regions of 3D cultures is possible, but relies
on low-throughput techniques such as tissue sectioning and micromanipulation.
Based on a procedure reported previously (“cells-in-gels-in-paper”
or CiGiP), this paper describes a simple method for culture of arrays of thin
planar sections of tissues, either alone or stacked to create more complex 3D
tissue structures. This procedure starts with sheets of paper patterned with
hydrophobic regions that form 96 hydrophilic zones. Serial spotting of cells
suspended in extracellular matrix (ECM) gel onto the patterned paper creates an
array of 200 micron-thick slabs of ECM gel (supported mechanically by cellulose
fibers) containing cells. Stacking the sheets with zones aligned on top of one
another assembles 96 3D multilayer constructs. De-stacking the layers of the 3D
culture, by peeling apart the sheets of paper, “sections” all 96
cultures at once. It is, thus, simple to isolate 200-micron-thick
cell-containing slabs from each 3D culture in the 96-zone array. Because the 3D
cultures are assembled from multiple layers, the number of cells plated
initially in each layer determines the spatial distribution of cells in the
stacked 3D cultures. This capability made it possible to compare the growth of
3D tumor models of different spatial composition, and to examine the migration
of cells in these structures
Strategies to prevent intraoperative lung injury during cardiopulmonary bypass
During open heart surgery the influence of a series of factors such as cardiopulmonary bypass (CPB), hypothermia, operation and anaesthesia, as well as medication and transfusion can cause a diffuse trauma in the lungs. This injury leads mostly to a postoperative interstitial pulmonary oedema and abnormal gas exchange. Substantial improvements in all of the above mentioned factors may lead to a better lung function postoperatively. By avoiding CPB, reducing its time, or by minimizing the extracorporeal surface area with the use of miniaturized circuits of CPB, beneficial effects on lung function are reported. In addition, replacement of circuit surface with biocompatible surfaces like heparin-coated, and material-independent sources of blood activation, a better postoperative lung function is observed. Meticulous myocardial protection by using hypothermia and cardioplegia methods during ischemia and reperfusion remain one of the cornerstones of postoperative lung function. The partial restoration of pulmonary artery perfusion during CPB possibly contributes to prevent pulmonary ischemia and lung dysfunction. Using medication such as corticosteroids and aprotinin, which protect the lungs during CPB, and leukocyte depletion filters for operations expected to exceed 90 minutes in CPB-time appear to be protective against the toxic impact of CPB in the lungs. The newer methods of ultrafiltration used to scavenge pro-inflammatory factors seem to be protective for the lung function. In a similar way, reducing the use of cardiotomy suction device, as well as the contact-time between free blood and pericardium, it is expected that the postoperative lung function will be improved
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